Poultry processing plants typically use overhead shackle conveying systems to transfer poultry carcasses through different processing operations. Overhead shackle lines generally run at constant speeds. The overhead shackle lines are continuous loop conveying systems with shackles spaced on a constant pitch, that is, a constant distance apart. The poultry carcasses, which could be chicken, turkey or duck carcasses, are generally suspended from the conveying shackles. The carcasses may be suspended by both legs, by one leg, by both wings, by one wing, or the neck. During normal operation, the majority of the shackles are loaded with carcasses. However, some of the shackles are empty. Throughout the shackle conveying process, the carcasses (birds) are selectively unloaded or ejected from the shackles depending on their size or weight and/or the requirements of each processing step. In order to properly track the changing flow of poultry carcasses, poultry processors will attach bird counting photo sensors and shackle counting electrical photo sensors onto the overhead line at different points along the path of travel defined by the line.
The consistent counting of poultry carcasses on moving shackles continues to be a challenge for poultry processors. Conventional carcass and shackle counting systems generally use electrical photo sensors. One set of photo sensors is used for counting the shackles. A second set of photo sensors is used for counting the poultry carcasses. The photo sensors are mounted to the track and are used with an electronic control system. The use of photo sensors to count shackles has generally been a reliable process. However, the use of photo sensors to count poultry carcasses have been inaccurate due to bird swinging in front of a photo sensor when the line stops, varying bird sizes, improperly hung birds and sensor blockage.
What is needed is a system for conveying and counting poultry that provides for accurate counting of poultry carcasses at one or more points along a poultry conveying line. What is also needed is a system for conveying and counting poultry that provides a visual display of the poultry count at one or more points along the poultry conveying line. What is also needed is a system for conveying and counting poultry that discriminates between a true count of a poultry carcasses and a false carcass count caused by, for example, a poultry carcass swinging in the path of or against a sensor or counter.